The invention relates to the field of fluorescent lamps, and in particular to a fluorescent lamp with an integral proximity sensor for building energy management.
Lighting in commercial and residential spaces consumes a significant portion of the end use demand for delivered energy in the United States. In 2005, lighting consumed 0.73 Quadrillion Btu (QBtu) in the residential sector and 1.18 QBtu in the commercial sector. This accounts for 15.6% and 13.9% of the total electricity delivered in the residential and commercial sectors, respectively; approximately $20.1 billion and $29.7 billion spent by electricity consumers in the residential and commercial sectors, respectively. The invention relates to the field of fluorescent lamps, in particular a fluorescent lamp with an integral proximity sensor for building energy management.
The U.S. Environmental Protection Agency (EPA) encourages reduction of energy consumption by improving efficiency of energy systems. The EPA's Energy Star program provides energy efficient solutions for reducing energy consumption while maintaining or improving the current standards of living. The Energy Star program also recognizes businesses and organizations for reducing greenhouse gas emissions through energy efficiency. “In 2006 alone, Americans with the help of Energy Star saved $14 billion on their energy bills and avoided greenhouse gas emissions equivalent to those of 25 million vehicles.
One implementation strategy for reducing energy consumption described by the Energy Star program is to reduce lighting in unoccupied spaces using motion sensors to detect occupants. Motion sensors monitor large spaces and turn lights on and off based on occupant motion. In principle, they reduce the energy consumed by lights in unoccupied spaces. There are several disadvantages associated with detecting occupancy using motion sensors. First, the occupancy measurement is often based on motion rather than presence. To turn on the lights, occupants must periodically move in view of the sensor. Unfortunately, lights can turn off despite occupancy and stay on for some time after the occupants have left. Second, the motion detectors require custom installation distinct and in addition to the installation of luminaires. There is a premium on minimizing sensor hardware and installation expense, and measurement networks are often as coarse grain as possible to implement a basic level of functionality. Typical motion sensor implementations may allocate one motion sensor to an entire large room. If the rooms are sparsely occupied, there is still significant wasted energy on lighting unoccupied spaces. Finer grain lighting control increases sensor expense and installation effort.
The invention provides a novel technique in managing the energy expended by lighting systems.